Device for the continuous determination of the lubricant requirement of a movable sliding surface

ABSTRACT

This invention relates to a device for the continuous determination of the lubricant requirement of a sliding surface movable against a fixed sliding surface by measuring the force for overcoming the friction between the movable sliding surface and a reciprocating sensor member urged against the sliding surface with the constant contact pressure, said device comprising a supporting bar slidably mounted on a support plate, said supporting bar mounting a sensor member at one end and having its other end connected by a crank rod to an eccentric drive, the plate carrying a motor to actuate the eccentric drive to reciprocate the supporting bar. The end of the plate adjacent the eccentric is pivotally mounted on a first axis parallel to the movable sliding surface and on a second axis perpendicular to the movable sliding surface, a first resilient means reacting against the plate to urge said sensor member against the movable sliding surface and a second resilient means reacting against the plate to urge said sensor member in direction opposed to the direction of movement of the movable sliding member, means being provided actuated by movement of the sensor a predetermined amount in the direction of movement of the movable sliding surface to actuate lubricating means for such movable sliding surface.

United States Patent [1 1 Vernazza et al.

[ Feb. 12, 1974 DEVICE FOR THE CONTINUOUS DETERMINATION OF THE LUBRICANT REQUIREMENT OFA MOVABLE SLIDING SURFACE [75] Inventors: Julius Vernazza; Oskar Marx, both of Aachen, Germany [73] A ssignee: I1. Krantz, Aachen, Germany [22] Filed: Oct. 24, 1 972 [21] Appl. No.: 300,194

[30] Foreign Application Priority Data Oct. 26, 1971 Germany 2153173 [52] US. Cl. 184/5, 73/9 Primary ExaminerManuel A. Antonakas Attorney, Agent, or FirmArthur B. Colvin l 5 ABSTRACT This invention relates to a device for the continuous determination of the lubricant requirement of a sliding surface movable against a fixed sliding surface by measuring the force for overcoming the friction between the movable sliding surface and a reciprocating sensor member urged against the sliding surface with the constant contact pressure, said device comprising a supporting bar slidably mounted on a support plate, said supporting bar mounting a sensor member at one end and having its other end connected by a crank rod to an eccentric drive, the plate carrying a motor to actuate the eccentric drive to reciprocate the supporting bar. The end of the plate adjacent the eccentric is pivotally mounted on a first axis parallel to the movable sliding surface and on a second axis perpendicular to the movable sliding surface, a first resilient means reacting against the plate to urge said sensor member against the movable sliding surface and a second resilient means reacting against the plate to urge said sensor member in direction opposed to the direction of movement of the movable sliding member, means being provided actuated by movement of the sensor a predetermined amount in the direction of movement of the movable sliding surface to actuate lubricating means for such movable sliding surface.

1 DEVICE FOR THE CONTINUOUS DETERMINATION OF THE LUBRICANT REQUIREMENT OF A MOVABLE SLIDING SURFAE The need for determining the lubricant requirement of movable sliding surfaces arises from the fact that too little lubrication accelerates the wear of the sliding surfaces and requires increased drive power, whereas with excessive lubrication, apart from the increased consumption of lubricant, undesirable side effects may occur. Thus, for example, for the lubrication of the bearings and guideway of tensioning chains in fabric te'ntering, drying, or fixing machines in which the web of material is exposed to highly heated circulating gases, the danger of damage to the' web at excessive lubrication is particularly great, because either the excess lubricant directly spots the cloth or, due to evaporation of the volatile constituents, lubricant particles increasingly become mixed with the circulated treatment gas so that they will eventually precipitate on the cloth and soil or degrade it.

An attempt has been made before to determine the lubricant requirement of the guide rails of tenter chains by measuring the force lengthwise of the chains. The reference value used is the current consumption of a d-c motor driving the chain. However, because the current consumption of the drive motor is not influenced solely by the state of lubrication of the chain, but is also subject to variations due to variable transverse tension of the cloth web, comparative values which would permit an objective evaluation of the state of lubrication cannot be determined by this measurement.

A device is also known for determining the lubricant requirement where the sliding surface to be lubricated is scanned at constant contact pressure crosswise to its direction of movement and the power requirement for this is measured by the load current of a d-c shunt motor connected to constant voltage.

By the scanning of the sliding surface crosswise to its direction of'movement, the effect of the velocity of the sliding surface is reduced to an insignificant amount. The constant contact pressure, on the other hand, makes sure that different tranverse tensions, as they occur for example, at the sliding surfaces of tenter frame chains due to different cloth pull in transverse direction, remain without influence on the measured value, so that the load current for the power requirement of the scanning constitutes a true reference value for the state of lubrication of the sliding surface.

It is however a disadvantage of this known device that the load current of the d-c shunt motor stays within very narrow limits, due to which the reading of the measurement result is imprecise.

In practice, therefore, the state of lubrication of sliding surfaces continues to be evaluated subjectively and requires continual reliable observation by the operator, wthout guarantee of an optimum state of lubrication of the sliding surfaces.

It is among the objects of the invention to provide a device which permits objective continual determination of the lubricant requirement of a movable sliding surface and by means of which the release of lubricant can be controlled accordingly, which device is of sturdy construction and reliable in operation and does away with sensitive measuring instruments and releases the lubricant supply in accordance with the requirement determined, without intervention of the operator.

According to the invention, the device for the continual determination of the lubricant requirement of a movable sliding surface comprises means for sensing the force for overcoming the friction between the movable sliding surface and a vibrating sensor applying load on the sliding surface with constant contact pressure. For this purpose the sensor is mounted on a supporting bar which at its free end is connected'with a crank rod of an eccentric. A guide member for the supporting bar is mounted with the eccentric on a plate crossing the sliding surface, which plate is mounted at one end on an axis parallel to the sliding surface and is provided at the other end with a spring pivoting said other end of the plate in direction toward the sliding surface. Furthermore, according to the invention, the plate is also pivotally mounted about an axis perpendicular to the sliding surface and adjustable spring means are provided normally urging the plate in direction opposed to the direction of movement of the movable sliding surface, and means being associated with the plate to release the lubricant supply.

According to a particularly advantageous embodiment of the invention, the axis parallel to the sliding surface and the axis perpendicular to the sliding surface are joined to form a universal joint. The universal joint favors in particular a compact construction of the plate suspension.

According to a specific form of the device, the mov- V able sliding surface is associated with a fixed sliding surface, having an opening in which the sensor is positioned in contact with the movable sliding surface. This design'permits a protected accommodation of the sensor and largely eliminates extraneous influences on the sensor indicating the friction force.

Lastly, the invention also provides that a sleeve fastened on the plate or pulley pairs with circumferential grooves, rotatably mounted on the plate, serve as guide member of the supporting bar.

The device of the invention is excellently suited also for subsequent installation on sliding surfaces and permits a continual determination of the optimum lubricant requirement to be insured at low cost.

In the accompanying drawing, an example of construction of the device of the invention is illustrated in the example of a tenterhook chain connection, as used in tenter frames for fabric transport.

FIG. 1 shows the device in a vertical transverse section, and

FIG. 2 in a side view.

Referring now to the drawings, In FIG. 1 a tenterhook body 1 is provided which is connected with a link 2 of a chain. The tenterhook chain runs in a rail 3, which for the conduction of the chain comprises a horizontal leg 4 and a vertical leg 5.

The vertical leg 5 has a groove 6 and the sliding surface 7 of a yoke 8 of the tenterhook body 1, bears against the wall of groove 6 forming a fixed sliding surface 9. The sliding surface 7 ispressed against the fixed sliding surface 9 by a leaf spring 10 positioned in groove 6 and which is supported by a cylindrical compression spring 11. The horizontal leg 4 carries the tenterhook chain.

The wall of groove 6 \m'th the sliding surface 9 has an opening 12 in which a sensor 13 is accommodated,

which bears against the movable sliding surface 7 of the yoke 8.

The sensor 13 is mounted on one end of a supporting bar 14 which traverses the vertical leg of the guide rail 3 through a bore 15. The bore diameter is selected so that the supporting bar 14 of the sensor 13 can execute in the bore 15 a pivotal movement in addition to a vertical movement.

An elongated plate 18 is povitally mounted at its lower end on an axis 17 arranged parallel to the sliding surface 7. The plate 18 is further pivotally mounted on an axis 19 normal to the sliding surface 7 and perpendicular to axis 17. If desired, the axes 17 and 19 may comprise a universal joint.

For the guiding of the supporting bar 14, there are mounted on-plate 18, pulley pairs 20 and 21 which, as shown in FIG. 2, have grooves 22 for secure guiding of the supporting bar 14.

The lower end of the supporting bar 14 is connected with a crank rod 23, which is mounted in an eccentric 24. The eccentric is driven by way of a reducing gear (not shown). by an electric motor M mounted on plate 18.

A tension spring 25 is provided having an end connected to theupper end of plate 18 and its other end connected to a bracket 26 fastened to the guide rail 3 to urge the sensor 13 against the sliding surface 7.

An adjustable coil spring 27 is also provided having one end secured to the plate 18 near its upper end, and its other end secured to a fixed support. The spring 27 normally uges the plate 18 in direction away from lubrication control limit switch 28, i.e., in direction opposed to the direction of movement of chain 2.

The operation of the device is as follows:

To determine the lubricant requirement during the revolution of the chain 2 the electric motor, connected to constant voltage; is switched on, so that the eccentric 24 through the crank rod'23 moves the suppoting bar 14 up and down cross wise to the horizontal running direction of the chain 2.

Due to the tension spring 25, the sensor 13 is pulled at constant .contact pressure against the movable sliding surface 7 and the sensor is subject, during the movement transverse to the running direction of the chain, depending on the state of lubrication of the sliding surface 7, to a certain frictional force which is not influenced by the different tensions at the tenterhook body 1.

The adjustable coil spring 27 (FIG. 2), which acts parallel to the running direction of the chain, but in the opposed direction to the movement of the latter, absorbs the frictional force. As a certain frictional force is exceeded, the plate 18 will pivot to the left (FIG. 2) until limit switch 28 is actuated, which releases the lubricant supply, the switch 28 controlling a valve (not shown) which releases a jet of lubricant onto the sliding surfaces. Exceeding a certainffrictional force is thus a reliable indication of the lubricant requirement of the sliding surface 7. Because of the sensor 13 which is moved relatively to the direction of movement of the sliding surface, and which sensor extends over several adjacent sliding surfaces 7 simultaneously, different velocities of the chain remain without practical influence on the release of the lubricant supply.

Having thus described our invention, what we claim as new and desire to secure by Letters Patent of the United States is:

l. A device for the continual determination of the lubricant requirement of a movable sliding surface against a fixed sliding surface, comprising a movable sliding surface and a fixed sliding surface, a sensor member, means mounting said sensor member for movement toward such movable sliding surface and for movement back and forth in direction substantially parallel to the direction of movement of such movable sliding surface with respect to such fixed surface, first means resiliently urging said sensor member against such movable sliding surface, second means resiliently urging said sensor member in direction opposed to the direction of movement of such movable sliding surface, means to lubricate such movable sliding surface and means actuated by movementof the sensor a predetermined amount in the direction of movement of such movable sliding surface, to actuate such lubricating means.

2. The combination set forth in claim 1 in which said first resilient means urges said sensor member with constant force against said movable sliding surface.

3. The combination set forth in claim 1 in which said second resilient means is adjustable.

4. The combination set forth in claim 1 in which means are provided to effect reciprocating movement of said sensor member in direction transverse to the direction of movement of said movable sliding surface.

5. The combination set forth in claim 1 in which the fixed sliding surface has an opening in which the sensor is positioned in contact with the movable sliding surface.

6. The combination set forth in claim 1 in which the means mounting said sensor member comprises a support plate, a supporting bar slidably mounted on said plate, said sensor member being mounted on one end of said bar, an eccentric drive on said plate, a crank rod connecting said eccentric drive to the other end of said bar, means to rotate said eccentric drive to reciprocate said bar and said sensor member, and means at the end of the plate adjacent the eccentric drive pivotally to mount the plate on a first axis parallel to the movable sliding surface, and on a second axis perpendicular to the movable sliding surface.

7. The combination set forth in claim 6 in which the means resiliently urging said sensor member against such movable sliding surface comprises a coil spring reacting against said plate in direction to pivot the latter on said first axis.

8. The combination set forth in claim 6 in which the means resiliently urging said sensor member in direction opposed to the direction of movement of such movable sliding surface comprises a coil spring reacting against said plate in direction to pivot the latter on said second axis.

9. The combination set forth in claim 6 in which the axis parallel to the sliding surface and the axis of said plate perpendicular to the sliding surface are joined together to form a universal joint.

10. The combination set forth in claim 6 in which guide means for the supporting bar are mounted on the plate.

11. The combination set forth in claim 10 in which the guide means comprises two pairs of circumferentially grooved pulleys, the pulleys of each pair being transversely aligned and the, pairs of transversely plate. 

1. A device for the continual determination of the lubricant requirement of a movable sliding surface against a fixed sliding surface, comprising a movable sliding surface and a fixed slIding surface, a sensor member, means mounting said sensor member for movement toward such movable sliding surface and for movement back and forth in direction substantially parallel to the direction of movement of such movable sliding surface with respect to such fixed surface, first means resiliently urging said sensor member against such movable sliding surface, second means resiliently urging said sensor member in direction opposed to the direction of movement of such movable sliding surface, means to lubricate such movable sliding surface and means actuated by movement of the sensor a predetermined amount in the direction of movement of such movable sliding surface, to actuate such lubricating means.
 2. The combination set forth in claim 1 in which said first resilient means urges said sensor member with constant force against said movable sliding surface.
 3. The combination set forth in claim 1 in which said second resilient means is adjustable.
 4. The combination set forth in claim 1 in which means are provided to effect reciprocating movement of said sensor member in direction transverse to the direction of movement of said movable sliding surface.
 5. The combination set forth in claim 1 in which the fixed sliding surface has an opening in which the sensor is positioned in contact with the movable sliding surface.
 6. The combination set forth in claim 1 in which the means mounting said sensor member comprises a support plate, a supporting bar slidably mounted on said plate, said sensor member being mounted on one end of said bar, an eccentric drive on said plate, a crank rod connecting said eccentric drive to the other end of said bar, means to rotate said eccentric drive to reciprocate said bar and said sensor member, and means at the end of the plate adjacent the eccentric drive pivotally to mount the plate on a first axis parallel to the movable sliding surface, and on a second axis perpendicular to the movable sliding surface.
 7. The combination set forth in claim 6 in which the means resiliently urging said sensor member against such movable sliding surface comprises a coil spring reacting against said plate in direction to pivot the latter on said first axis.
 8. The combination set forth in claim 6 in which the means resiliently urging said sensor member in direction opposed to the direction of movement of such movable sliding surface comprises a coil spring reacting against said plate in direction to pivot the latter on said second axis.
 9. The combination set forth in claim 6 in which the axis parallel to the sliding surface and the axis of said plate perpendicular to the sliding surface are joined together to form a universal joint.
 10. The combination set forth in claim 6 in which guide means for the supporting bar are mounted on the plate.
 11. The combination set forth in claim 10 in which the guide means comprises two pairs of circumferentially grooved pulleys, the pulleys of each pair being transversely aligned and the pairs of transversely aligned pulleys being longitudinally spaced on said plate. 